[0001] The present invention relates to an improvement in a fire alarm and detection system
of the type previously disclosed, for example, in one of assignee's related applications
entitled, "Line Monitor for Two Wire Data Transmission", now patent 5,670,937. More
particularly the improvement herewith has to do with the ability to automatically
synchronize the power supplied from different sources to the different alarm devices
of the system.
BACKGROUND AND OBJECT OF THE INVENTION
[0002] Reference has been made above to assignee's particular fire alarm and detection system
as described in U.S. patent 5,670,937. The description of that patents system is incorporated
herein by reference. In essence, that system - aside from the particular line monitor
feature -- forms the context or environment for the inventive improvement to be described.
[0003] Other examples of prior systems of this general type can be appreciated by reference
to U.S. patents 4,568,919, 4,752,698, 4,850,018, 4,954,809 and 4,962,308. Most of
these U.S. patents describe systems that include a loop controller or the like which
initiates the determination of the states of the units or transponders at various
zones or stations in the system, typically by repetitive polling of the stations,
whereby addresses are sent successively on the loop or lines to determine which, if
any, units are in an alarm state; any units reporting an alarm state receive back
from the loop controller an activate relay command. Provision is also made of most
of these systems to detect and report trouble conditions.
[0004] In providing alarm signals at particular stations or locations, it is the common
practice to supply power to strobes which provide flashing light and to horns which
produce non-continuous sounds. However, a problem arises when the sources of light
and sound are operating such that the sources lack synchronization of the power being
supplied to them; hence, they will produce confusion during an alarm situation. For
example, an aberrant mixture of unsynchronized light pulses or horn blasts may give
rise to confusion of signals, thus frustrating efficient warning to occupants of the
emergency conditions.
[0005] It can be appreciated that the desired synchronization of alarm signals from the
aforesaid typical strobes and horns and the like is difficult when it has to be accomplished
over large areas because there is a need to power such output devices from multiple
power supplies that differ in operating characteristics.
[0006] Accordingly, it is the primary object of the present invention to improve the already
known fire alarm systems of the type described in U.S. patent 5,670,937.
[0007] A further object of the present invention to solve the serious problem noted above,
i.e., of satisfying the need for appropriate synchronization of alarm devices that
are powered by a number of power supplies that tend to vary or drift such that, left
to themselves, are not capable of remaining in complete synchronization.
[0008] Another object is to improve upon a modules previously found in the earlier fire
alarm systems by providing specialized, more intelligent modules, sometimes referred
to as auto synchronous output modules, that will realize the needed synchronization
across many separated alarm zones.
SUMMARY OF THE INVENTION
[0009] Before proceeding with the summary of the present invention it is well to consider
certain definitions: a module when referred to hereinafter is an electronic circuit
that is provided at a number of zones in an alarm system and is interconnected over
the same wire or pair which extends through the plurality or multiplicity of zones.
[0010] It should be especially noted that, typically, a multiplicity of modules in respective
zones of an alarm system loop are in eight groups, with sixteen modules in each group,
and individual units may be addressed or selected.
[0011] In fulfillment of the objects already stated a fundamental aspect of the present
invention resides in the provision for overcoming the lack of synchronization of alarm
devices, particularly where light strobes and horn devices are involved, that would
otherwise cause rampant confusion in the alarm sounding operation which is intended
to alert occupants to existing unambiguously to hazardous conditions.
[0012] A first main feature of the present invention is defined as follows with reference
to the complete system:
[0013] A system for synchronizing the power supplied to alarm output devices at different
zones in a life safety system, wherein the output devices are controlled by auto synchronous
output modules at the respective zones and wherein the output devices are supplied
with power from different power sources comprising: a loop controller at a central
location; the modules including a power source and output devices; the modules being
connected in groups along a data loop for first receiving activate commands, followed
by synchronize commands, in the form of control signals from the loop controller so
as to activate the output devices, responsive to the loop controller sensing alarm
conditions at the zones; the modules including means operative when the synchronize
command is received for suspending the application of power to the output devices
for a predetermined time interval, whereby all activated output devices are synchronized.
[0014] Another feature resides in having an arrangement of a means for recognizing, once
a first group of modules have had their separate and different power supplies synchronized,
that subsequent synchronization command or signal is now being sent to additional
modules, and responding thereto so as to re-synchronize said first group of modules.
[0015] Yet another feature resides in a provision or means for providing periodic re-synchronization
based solely on the passage of a predetermined time interval so that the re-synchronization
of the power supplied by separate sources to output devices is updated on a continuous
basis.
[0016] Other and further objects, advantages and features of the present invention will
be understood by reference to the following specification in conjunction with the
annexed drawings, wherein like parts have been given like numbers.
BRIEF DESCRIPTION OF THE DRAWING
[0017] Figure 1 is a functional block diagram which provides an simplified overview of the
system in which the present invention is incorporated to constitute a unique group
of transponder modules in such system.
[0018] Figure 2 is a block-schematic diagram of a class B dual input arrangement for a universal
class A/B module incorporating the present invention.
[0019] Figure 3 is a block diagram of part of a system, and particularly illustrating a
variety of devices in the form of smoke detectors and other devices connected to a
universal transponder module at a given zone or station.
[0020] Figure 4 is a schematic diagram of a transponder, including a module.
[0021] Figure 5 is a magnified view of the microcontroller of the universal module of Figure
4A.
[0022] Figure 6 is a timing diagram illustrating the application of inputs to the data lines
from the loop controller.
[0023] Figure 7 is a flow chart of the firmware within the microprocessor forming part of
the auto synchronous output module of the present invention, such firmware incorporating
the synchronous relay routine to be carried out by the microprocessor or microcontroller
in response to the instructions embodied in the programmed firmware.
[0024] Figures 8A is a timing diagram of the activate command and synchronize command signals
which are sent from the loop controller; Figure 8B is a timing diagram of the output
device power controlled by the auto synchronous output module; Figure 8C is the timing
cycle for the device power.
DESCRIPTION OF PREFERRED EMBODIMENTS
System and Common Module Circuitry
[0025] Referring now to Figures 1-4 and more particularly for the moment to Figure 1 of
the drawing, there will be seen a simplified showing of the system context in which
the present invention operates to fulfill the fundamental object of synchronizing
the power sources in the loops of the fire detection and alarm system so as to avoid
the drift from synchronism that would naturally take place.
[0026] In Figure 1, the loop controller 10 is connected by multiple-wire outgoing and return
cable 12 to a first transponder unit 16 which, in turn, is connected by a multiple-wire
cable 14 to the next unit 16 and so on to other units.
[0027] Within the uppermost unit 16, there are seen a block designated 22 representing common
components of a transponder module 24 whose inputs/outputs are represented by pairs
of lines 18 and 20, which are supplied, typically with 24 v DC, and can be variously
connected by the module to provide different modes of operation for the transponder
16. Also seen connected to the lower part of the common components 22 of the module
24 are several features forming parts of the module circuitry: a "personality" feature
26 which involves selective programming of a microcontroller, which forms the centerpiece
of the module 24, such that various prescribed functions can be realized by the given
module depending on the configuration code chosen. This personality feature is described
and claimed in U.S. patent 5,701,115 the disclosure of which is incorporated herein
by reference.
[0028] The ground fault detector feature 30 is described and claimed in docket 100.0601.
The stand alone feature 32 is described and claimed in docket 100.0603 and the load
shedding feature 34 is described and claimed in docket 100.0604; the details of all
of the preceding features being incorporated herein by reference to their respective
patent applications already noted.
[0029] Referring now to Figure 2 of the drawing, there is depicted the module 24 which is
a universal module and can be arranged, in this example, to operate class B, as a
dual input module. Moreover, in this figure, connections of "data in" lines and "data
out" lines are seen made to terminal blocks at the bottom of the modules, these lines
corresponding, respectively, to lines 12 and 14 in Figure 1. However, not seen in
Figure 1 are the particular class B input connections of Figure 2, which are effectuated
by the switch contacts 40, representing typical initiating devices, in input circuit
1 and, similarly, the contacts 42 in input circuit 2.
[0030] If a particular personality code, for example, personality code 1 is assigned to
both of the input circuits seen in Figure 2, this configures either one or the other
or both circuits for class B normally open, involving dry contact initiating devices
such as pull stations, heat detectors, etc. Consequently, when an input contact is
closed an alarm signal is sent to the loop controller and the alarm condition is latched
at the module 24.
[0031] Figure 3 illustrates the system where focus is on the selected circuitry or circuitry
pathways extending from the universal module 24, as previously discussed, is a part
of a transponder unit 16 located at a given zone or station. The module 24 is depicted
in association with a variety of devices in, for example, input circuits. Such devices
can be selected as a package with such universal module 24, or the module can be incorporated
into an already existing system, that is, retrofitted to an older style system to
bring it up-to-date. Thus, as shown in Figure 3, two loops extend from the upper portion
of the module. One loop includes a heat detector 50, an end of line resistor 52 and
a conventional smoke detector 54. In the other loop there is a manual station 56,
and two conventional smoke detectors 58, 60 with an end of line resistor 62 for that
other loop.
[0032] Also connected to the universal module 24, in yet another loop, is a plurality of
intelligent devices, including a monitor module 70 and associated therewith a manual
station 72, and an end of loop resistor 74. Also extending, in a further loop, from
the afore-noted monitor module 70 is an intelligent analog heat detector 80, an intelligent
analog smoke detector 82, and analog manual stations 84 and 86.
[0033] Figures 4A through 4D and 4A' through 4C' are combined to form a schematic diagram
of the module 24. The module circuitry has at the lower right in Figure 4C the connection
from the loop controller to the "data in" lines 12 at the terminals designated TB
14, TB 1-3; as well as the connection to the next transponder unit at another location
(see at the very bottom of the figure) by way of the "data out" lines 14 from terminals
TB 1-2, TB 1-1.
[0034] It will be appreciated that data communication is accomplished over the aforesaid
lines, as well as synchronous, large signal, transmission. As one example, interrupt
(command) signals from the loop controller are transmitted to the module 24 over the
"data in" lines (designated 12 in Figure 1), three levels of interrupt command voltages
being available; that is, zero volts, 9 volts, or 19 volts can be transmitted from
loop controller 10.
[0035] The loop controller sends messages out by changing the line voltage between 0, 9,
and 19 volts. The devices respond by drawing 9 ma of current during specific time
periods. The basic time period of the protocol is given by:

[0036] The loop controller uses a basic time period of 1/2 T (0.976 ms) because it has to
sample the loop voltage and current in the middle of the data bits.
[0037] The start-up message, or interrupt mechanism, is specific and recognized by the module
as follows: (Also, see Figure 6).
1. The line voltage (across data lines 12) is initially at 19 volts for at least 2
time periods.
2. The line is held at 0 volts for 3 time periods.
3. The line goes to 9 volts for a 1 time period - this is the wake-up or interrupt
bit and modules synchronize on this edge.
4. The line alternates between 9 and 19 volts for n T periods, where n is the number
of data bits in the message.
5. The parity bit (even) follows the data bits.
6. The stop bit puts the line at 19 volts for 2 T periods, then the next message may
be sent.
[0038] The voltages noted above are transmitted by way of internal connection 90 to a discriminator
circuit 92 at the upper left in Figure 4, whose output is connected from the uppermost
node 94 of circuit 92, via inputs 13 and 42 to input ports of microcontroller 96.
The discriminator circuit 92 also includes another output, taken at note 98, to a
terminal 43 of the microcontroller. This microcontroller is selected to have an NEC
microprocessor therein, as well as an EE PROM 126 manufactured by EXCEL.
[0039] As will be appreciated, the discriminator circuit insures that when 19 volts is received
from the loop controller, such value is sufficient to exceed the upper threshold set
by the circuit and hence inputs 13 and 42 are active, whereas when only 9 v appear,
only input 42 is active.
[0040] It should be noted that the centerpiece or control device for the module 24 is the
microcontroller 96. A number of input/output ports (PO.O, etc.) to which connecting
terminals are provided, are shown on each side of the microcontroller, as well as
connections made to the top and bottom thereof. It will be noted that a ground connection
is made at the bottom of the microcontroller (Vss) and a bias connection (3.3 volts)
at the top terminals 25 and 28, as well as a connection from terminal 25 to terminal
29 on the right side of the microcontroller.
[0041] A group of terminals 22-27 are provided for reset and for timing control of the microcontroller,
the timing control connection being made to a timing circuit 100, provided with two
clocks 102 and 104.
[0042] Another group of terminals are used for reference and average bias manual connections,
such being designated terminals 30, 31 and 40, the 3.3 volt bias, terminal 30 to an
input/output port at terminal 5; and terminals 31 and 40 to ground.
[0043] Groups of analog/digital ports are connected to the terminals designated 33, 37-39
of the microcontroller, the first being a vector input from circuit 112; the last
three - being monitoring terminals, as will be explained hereafter.
[0044] A further group of terminals 18-21 are connected to input/output ports of microcontroller
96, which are, in turn, connected to relay cards for purposes to be explained. Another
terminal on the right of the microcontroller is terminal 48, connected to "load shed"
line 101 for purposes explained in connection with a load shed feature in accordance
with the related invention described in U.S. patent application S.N.08,441,762.
[0045] Other groups of terminals, connected with output ports, appear on the left of the
microcontroller. The group 53-55 is shown connected to circuitry at the lower portion
of Figure 4 and which will be explained. These output ports provide communication
back to the main or control panel, terminal 53 being connected by the connecting means
110 to the output of circuit 112 at the bottom of the figure and, hence, terminal
53 connects to an input port of the microcontroller; whereas 54 and 55 connect to
the respective circuits 114 and 116 which are LED circuits, that is, circuits for
illuminating LED's at appropriate times. Further portions of the circuitry involve
a peak detector 118 and a bias circuit 120 which, as can be seen, has the node 122
and supplies the bias of 3.3 volts for the microcontroller 96. A watchdog circuit
124 is seen immediately above the bias circuit 120, having a connection 121 to the
microcontroller at terminal 62. Another group of four input/output ports is connected
by respective terminals 57 through 60 to terminals of a 64 bit register 126. It will
be seen that a connection from terminal 8 of the microcontroller is made to terminal
8 of register 126 for the purpose of providing a "strobe" to the register 126 in order
to read the unit's identifying number stored in such register.
[0046] A reset circuit 130 furnishes a Reset + signal by way of the connection 132 to the
clock circuit 100, the amplifier 133 in such circuit being biased from the 3.3 volts
supply provided at node 122.
[0047] It will be noted that output terminals 18-21 of microcontroller 96 extend, by means
of respective connections 150, 152, 154, and 156, to respective operational amplifiers,
160, 162, 164, and 166. The former two, that is, 160 and 162 are connected to respective
ends of coil 168 and a trouble circuit 170 (which can be operated in class A, if desired),
whereas, the operational amplifiers 164 and 166 are connected to opposite ends of
relay coil 172, thus defining an alarm circuit 174.
[0048] Each of the relays in the trouble and alarm circuits is a double-pole, double throw,
each involving four relay contacts, two being shown open and two being shown closed
in each circuit
[0049] The smoke detector 201 is seen connected across terminals TB 3-11 and TB 3-12; thence,
by connecting means 203 and 205 to the respective points between pairs of alarm relay
contacts 207 and 209. Alternative devices, such as bell or speaker 211 are similarly
connected when called for -- being accomplished -- by selecting appropriate states
for the relay contacts 203, 205, 207 & 209.
[0050] It will be understood that the specific type of device, i.e., bell, telephone, heat
detector, manual pull station, etc., that is selectively connected to the module is
dependent on the assigned personality, or set of configuration bits, that is sent
to the modules memory at the time of installation (and which set can be suitably changed
at a later time, as already explained). For example, if the personality that is sent
to the module is "2-wire smoke detector", then non-intelligent conventional-type 2-wire
smoke detectors would be connected to terminals 11 and 12. Conversely, if the personality
desired was to operate bells during alarm condition, the personality "Class B or Class
A Signal Output" would be assigned and bells would be connected to terminals 11 and
12, and no 2-wire smoke detectors would be allowed on this module. Likewise, other
selected personalities for the module would dictate other modes of operation for that
portion of the circuitry in which the devices are selectively connected.
AUTO SYNCHRONOUS MODULE FEATURE
[0051] Referring now to Figures 7 and 8, there is seen in the first of these figures a flow
chart that depicts the logical steps or operations in a routine performed in accordance
with programming means sometimes referred to as "firmware", embedded within the microcontroller
96 seen in Figure 4A.
[0052] As has been noted before, an appropriate activate command (Figure 8), for example,
a command signal of approximately 19 volts, is sent from the loop controller 10 seen
in Figure 1 to the modules 24 at each of the zones which are serviced by a given loop
or two-wire line such as 12-12 or 14-14. Specifically, the signals corresponding to
an activate command are sent out on the loop or line in response to one or more modules
indicating to the loop controller that each of them is in alarm.
[0053] It will be understood that, after so indicating an alarm state, a given module then
performs a step or operation, represented by block 500 in Figure 7, of monitoring
the data line or loop for an activate command which is expected to follow. When the
activate command is indeed received, (Yes output of decisional block 502) the next
operation proceeds which is represented by block 504, whereby a default timer is started
and operates for 5 seconds prior to a synch command being received. If the default
timer runs for the full 5 seconds indicated, then an output signal will be transmitted
from the controller 96 to the relay 172 seen in Figure 4C. Closure of normally open
contacts of the relay will cause 24 volts from a separate power source to be applied
to the electronic horns and strobe lights 211 of the given installation. In this case,
the desired synchronism of power sources is not realized.
[0054] As just noted, a default operation occurs if the synchronize command does not follow
the activate command within the default period. However, while the monitoring step
represented by block 506 is being carried out, i.e., the module 24 is awaiting a synch
command (Figure 8) from the loop controller 10. The synch command signal will eventually
produce the requisite synchronization of multiple modules that have been placed in
alarm and which may be in a variety of loops or data lines. Without this feature,
there is the problem already described of causing confusion due to the fact that different
power supplies are furnishing power to spaced output devices, e.g., strobe lights
and horns, in the system. As has been explained, this is due to the fact that different
power sources tend to drift slightly from each other and hence lose synchronism over
time.
[0055] At the next step or operation of the programming routine, represented by decisional
block 508, a determination is made as to whether the synch command has been received.
It will be understood particularly by referring to Figures 8A and 8B, and particularly
for the moment to Figure 8B, that once the synch command is received at time tl, there
is a time delay of 2 milliseconds before a synch pulse of 20 milliseconds duration
from the module 24 appears, the effect of which is to cause power drop-out. The dropout
period is seen in Figure 8B extending from the synch pulse edge 600 to edge 602. During
this period, with the relay 172 de-energized, hence, its contacts being open, no power
is being supplied to the output devices 211. However, this dropout period ends as
the voltage rises as shown by the edge 602 to the 24 volt value. It will be noted
that the decisional block 510 provides the operation of checking on whether the default
timer period has expired.
[0056] The step or operation represented by block 512 is logically connected to 508 and
510 such that in either event, that is, if the default time has expired or if the
synch command has been received there will be activation of a reset sequence. In case
of a default time having expired, power is applied to output devices from the controller
96 through the closure of contacts of relay 172; but in the event the synch command
has been received, the synch pulse indicated in Figure 8B will carry out its function
of causing power drop-out as already explained, with the ultimate effect of causing
all of the modules that have been activated to be reset and therefore to be synchronized
at approximately the same instant of time. This is indicated by the operations designated,
"Activate Reset Sequence" (512) and "Signals Reset" (514).
[0057] Several additional synchronization schedules or schemes are also features of the
present invention. Thus subsequent steps or operations represented by blocks 516 and
518 are carried out, by which resynchronization is achieved of a previously synchronized
group of auto synchronous output modules when another module or modules on the same
loop are being synchronized. This will be appreciated by reference to Figure 8A which
shows a timing diagram over a significantly longer period than that seen in Figure
8B. In this diagram one sees the activation of a series or group of ASO modules ASO
#1, #2 and #3, as well as ASO #N-1 and ASO #N. Further along the timing diagram is
ASO N+1. Thus it will be seen that the synchronize--commands all active--pulse 604
will cause synchronization of the modules ASO #1 through N that have already been
activated. Likewise, after a period of five minutes, there will be a periodic synchronization
command transmitted such that if there has been any drift since the original synchronization
by 604 then this further pulse called a periodic pulse 606 (e.g., every five minutes)
will cause resynchronization of ASO #1 -- ASO #N.
[0058] Further on in the timing diagram of Figure 8A, it will be seen that at some point
another module ASO N+1 may be activated and this will cause re-synchronization of
all the prior modules ASO #1 through ASO #N just because this ASO N+1 is in the process
of being synchronized with the other modules in its group or loop. In order not to
interfere with the normal timing of power application to the output devices, i.e.,
to the strobes and horns 211, the desired re-synchronization is timed to occur, as
seen in Figure 8C, during a "space" (time interval) between horn blasts; as well as
between strobe flashes.
[0059] It will be understood by those skilled in the art that flow chart of Figure 7 represents
the software aspect of the present invention. Thus, a series of logical steps or operations,
in accordance with the process, as well as the means for performing such steps, is
illustrated by the blocks 500 to 518. It will be apparent that the particular hardware
can take a variety of forms but essentially well-known and conventional devices such
as storage means, (for example, the storage device 126 seen in Figure 4A), are utilized,
as well as flip-flops, timing devices and a variety of logic circuits, to perform
the required functions, thereby to achieve the primary object, namely, of overcoming
the lack of synchronization of output devices that might otherwise occur.
[0060] The invention having been thus described with particular reference to the preferred
forms thereof, it will be obvious that various changes and modifications may be made
therein without departing from the spirit and scope of the invention as defined in
the appended claims.
1. An auto synchronous output module for use at a plurality of zones in a fire alarm
and detection system comprising:
a power source and output devices selectively coupled to the power source so as to
provide audible and visual signals;
a microprocessor within the module for coupling to a data line so as to enable transmission
of data signals to and from a loop controller;
means within the processor, responsive to an activate command from the loop controller
for applying the power source to the output devices responsive to an alarm condition;
and
means within the processor, responsive to a synchronize command sent subsequently
to the activate command from the loop controller, for applying power to the output
devices in synchronism with application of other power sources to output devices at
other respective modules.
2. A module as defined in claim 1, in which the means for applying power to particular
output devices at in synchronism with applying power to output devices at other respective
modules includes means for interrupting power to all the devices for a predetermined
interval and then reapplying power.
3. A system for synchronizing the power supplied to alarm output devices at different
zones in a life safety system, wherein the output devices are controlled by auto synchronous
output modules at the respective zones and wherein the output devices are supplied
with power from different power sources comprising:
a loop controller at a central location;
the modules including a power source and output devices;
the modules being connected in groups along a data loop for receiving activate commands
in the form of control signals from the loop controller so as to activate the output
devices responsive to alarm conditions at the zones;
the modules including means operative when an activate command is received for suspending
the application of power to the output devices for a predetermined time interval until
a subsequent, synchronize command is received, whereby all activated output devices
are then synchronized.
4. A system as defined in claim 3, wherein all activated output devices are synchronized
by a synch pulse signal, including means for responding to the synch pulse signal
so as to interrupt the connection of the power sources to their respective output
devices.
5. A system as defined in claim 3, further including means for responding, following
initial synchronization at predetermined modules, to the subsequent synchronization
at other modules wherein said predetermined modules are then operative to resynchronize
the application of power to their alarm output devices.
6. A system as defined in claim 3, further comprising means for providing resynchronization
of all already synchronized modules after the passage of a predetermined period.
7. A system as defined in claim 7, wherein said means for responding to the synch pulse
signal includes a relay connected to said microprocessor for receiving said signal
therefrom.
8. A system as defined in claim 1, in which there are eight groups of said modules in
each data loop, sixteen modules being in each group.